Cool project and if it works for you and you're happy, that's all what counts.
When I read the article, I was thinking that Go templates were used wrong. I was thinking there must be a way to define the template so you inject the content and don't need to define the start and the end of the html, but instead yield a block of other html as some kind of argument. I was trying to look it up, but couldn't find documentation on this. Maybe the author is right and I'm wrong.
And I was wondering why the author isn't using something like Templ [0], which is kind of JSX with Go as hosting language. Probably because it needs the preprocessor / compile step?